[Mlir-commits] [mlir] [mlir][Vector] add vector.insert canonicalization pattern for vectors created from ub.poison (PR #142944)

[Diego Caballero]

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@@ -3191,6 +3227,109 @@ class InsertSplatToSplat final : public OpRewritePattern<InsertOp> {
   }
 };
 
+// Pattern to optimize a chain of constant insertions into a poison vector.
+//
+// This pattern identifies chains of vector.insert operations that:
+// 1. Start from an ub.poison operation.
+// 2. Insert only constant values at static positions.
+// 3. Completely initialize all elements in the resulting vector.
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dcaballe wrote:

we should probably also check that intermediate inserts have only one use to avoid an explosion of constants. I think we do something like that for the similar cases we have already.

https://github.com/llvm/llvm-project/pull/142944